What is this chick's breed?

I just recently went and bought more chicks. In the bin, there were Buff Orpingtons, Rhode Island Reds and Black Copper Marans. As the chick below is clearly not a Maran, the coloring is neither yellow or red. It is closer to the yellow of an Orpington, but it has a faint black line down the back of its head. Help please?